A 3rd generation partnership project (3GPP) long term evolution (LTE) system includes a frequency division duplexing (FDD) mode and a time division duplexing (TDD) mode. In LTE TDD and LTE FDD systems, a base station delivers a physical downlink control channel (PDCCH) to a user equipment (UE), where the PDCCH includes multiple kinds of scheduling information, such as a time-frequency resource position and a modulation and coding scheme used by the UE; and the UE sends uplink data and receives downlink data according to the PDCCH delivered by the base station.
The PDCCH includes multiple kinds of scheduling information; therefore, an overhead of a downlink control channel is relatively large, so that frequency spectrum efficiency is relatively low.